net/ipv4/icmp.c

   1 /*
   2  *      NET3:   Implementation of the ICMP protocol layer.
   3  *
   4  *              Alan Cox, <alan@lxorguk.ukuu.org.uk>
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License
   8  *      as published by the Free Software Foundation; either version
   9  *      2 of the License, or (at your option) any later version.
  10  *
  11  *      Some of the function names and the icmp unreach table for this
  12  *      module were derived from [icmp.c 1.0.11 06/02/93] by
  13  *      Ross Biro, Fred N. van Kempen, Mark Evans, Alan Cox, Gerhard Koerting.
  14  *      Other than that this module is a complete rewrite.
  15  *
  16  *      Fixes:
  17  *      Clemens Fruhwirth       :       introduce global icmp rate limiting
  18  *                                      with icmp type masking ability instead
  19  *                                      of broken per type icmp timeouts.
  20  *              Mike Shaver     :       RFC1122 checks.
  21  *              Alan Cox        :       Multicast ping reply as self.
  22  *              Alan Cox        :       Fix atomicity lockup in ip_build_xmit
  23  *                                      call.
  24  *              Alan Cox        :       Added 216,128 byte paths to the MTU
  25  *                                      code.
  26  *              Martin Mares    :       RFC1812 checks.
  27  *              Martin Mares    :       Can be configured to follow redirects
  28  *                                      if acting as a router _without_ a
  29  *                                      routing protocol (RFC 1812).
  30  *              Martin Mares    :       Echo requests may be configured to
  31  *                                      be ignored (RFC 1812).
  32  *              Martin Mares    :       Limitation of ICMP error message
  33  *                                      transmit rate (RFC 1812).
  34  *              Martin Mares    :       TOS and Precedence set correctly
  35  *                                      (RFC 1812).
  36  *              Martin Mares    :       Now copying as much data from the
  37  *                                      original packet as we can without
  38  *                                      exceeding 576 bytes (RFC 1812).
  39  *      Willy Konynenberg       :       Transparent proxying support.
  40  *              Keith Owens     :       RFC1191 correction for 4.2BSD based
  41  *                                      path MTU bug.
  42  *              Thomas Quinot   :       ICMP Dest Unreach codes up to 15 are
  43  *                                      valid (RFC 1812).
  44  *              Andi Kleen      :       Check all packet lengths properly
  45  *                                      and moved all kfree_skb() up to
  46  *                                      icmp_rcv.
  47  *              Andi Kleen      :       Move the rate limit bookkeeping
  48  *                                      into the dest entry and use a token
  49  *                                      bucket filter (thanks to ANK). Make
  50  *                                      the rates sysctl configurable.
  51  *              Yu Tianli       :       Fixed two ugly bugs in icmp_send
  52  *                                      - IP option length was accounted wrongly
  53  *                                      - ICMP header length was not accounted
  54  *                                        at all.
  55  *              Tristan Greaves :       Added sysctl option to ignore bogus
  56  *                                      broadcast responses from broken routers.
  57  *
  58  * To Fix:
  59  *
  60  *      - Should use skb_pull() instead of all the manual checking.
  61  *        This would also greatly simply some upper layer error handlers. --AK
  62  *
  63  */
  64
  65 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  66
  67 #include <linux/module.h>
  68 #include <linux/types.h>
  69 #include <linux/jiffies.h>
  70 #include <linux/kernel.h>
  71 #include <linux/fcntl.h>
  72 #include <linux/socket.h>
  73 #include <linux/in.h>
  74 #include <linux/inet.h>
  75 #include <linux/inetdevice.h>
  76 #include <linux/netdevice.h>
  77 #include <linux/string.h>
  78 #include <linux/netfilter_ipv4.h>
  79 #include <linux/slab.h>
  80 #include <net/snmp.h>
  81 #include <net/ip.h>
  82 #include <net/route.h>
  83 #include <net/protocol.h>
  84 #include <net/icmp.h>
  85 #include <net/tcp.h>
  86 #include <net/udp.h>
  87 #include <net/raw.h>
  88 #include <net/ping.h>
  89 #include <linux/skbuff.h>
  90 #include <net/sock.h>
  91 #include <linux/errno.h>
  92 #include <linux/timer.h>
  93 #include <linux/init.h>
  94 #include <asm/uaccess.h>
  95 #include <net/checksum.h>
  96 #include <net/xfrm.h>
  97 #include <net/inet_common.h>
  98 #include <net/ip_fib.h>
  99 #include <net/l3mdev.h>
 100
 101 /*
 102  *      Build xmit assembly blocks
 103  */
 104
 105 struct icmp_bxm {
 106         struct sk_buff *skb;
 107         int offset;
 108         int data_len;
 109
 110         struct {
 111                 struct icmphdr icmph;
 112                 __be32         times[3];
 113         } data;
 114         int head_len;
 115         struct ip_options_data replyopts;
 116 };
 117
 118 /* An array of errno for error messages from dest unreach. */
 119 /* RFC 1122: 3.2.2.1 States that NET_UNREACH, HOST_UNREACH and SR_FAILED MUST be considered 'transient errs'. */
 120
 121 const struct icmp_err icmp_err_convert[] = {
 122         {
 123                 .errno = ENETUNREACH,   /* ICMP_NET_UNREACH */
 124                 .fatal = 0,
 125         },
 126         {
 127                 .errno = EHOSTUNREACH,  /* ICMP_HOST_UNREACH */
 128                 .fatal = 0,
 129         },
 130         {
 131                 .errno = ENOPROTOOPT    /* ICMP_PROT_UNREACH */,
 132                 .fatal = 1,
 133         },
 134         {
 135                 .errno = ECONNREFUSED,  /* ICMP_PORT_UNREACH */
 136                 .fatal = 1,
 137         },
 138         {
 139                 .errno = EMSGSIZE,      /* ICMP_FRAG_NEEDED */
 140                 .fatal = 0,
 141         },
 142         {
 143                 .errno = EOPNOTSUPP,    /* ICMP_SR_FAILED */
 144                 .fatal = 0,
 145         },
 146         {
 147                 .errno = ENETUNREACH,   /* ICMP_NET_UNKNOWN */
 148                 .fatal = 1,
 149         },
 150         {
 151                 .errno = EHOSTDOWN,     /* ICMP_HOST_UNKNOWN */
 152                 .fatal = 1,
 153         },
 154         {
 155                 .errno = ENONET,        /* ICMP_HOST_ISOLATED */
 156                 .fatal = 1,
 157         },
 158         {
 159                 .errno = ENETUNREACH,   /* ICMP_NET_ANO */
 160                 .fatal = 1,
 161         },
 162         {
 163                 .errno = EHOSTUNREACH,  /* ICMP_HOST_ANO */
 164                 .fatal = 1,
 165         },
 166         {
 167                 .errno = ENETUNREACH,   /* ICMP_NET_UNR_TOS */
 168                 .fatal = 0,
 169         },
 170         {
 171                 .errno = EHOSTUNREACH,  /* ICMP_HOST_UNR_TOS */
 172                 .fatal = 0,
 173         },
 174         {
 175                 .errno = EHOSTUNREACH,  /* ICMP_PKT_FILTERED */
 176                 .fatal = 1,
 177         },
 178         {
 179                 .errno = EHOSTUNREACH,  /* ICMP_PREC_VIOLATION */
 180                 .fatal = 1,
 181         },
 182         {
 183                 .errno = EHOSTUNREACH,  /* ICMP_PREC_CUTOFF */
 184                 .fatal = 1,
 185         },
 186 };
 187 EXPORT_SYMBOL(icmp_err_convert);
 188
 189 /*
 190  *      ICMP control array. This specifies what to do with each ICMP.
 191  */
 192
 193 struct icmp_control {
 194         bool (*handler)(struct sk_buff *skb);
 195         short   error;          /* This ICMP is classed as an error message */
 196 };
 197
 198 static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
 199
 200 /*
 201  *      The ICMP socket(s). This is the most convenient way to flow control
 202  *      our ICMP output as well as maintain a clean interface throughout
 203  *      all layers. All Socketless IP sends will soon be gone.
 204  *
 205  *      On SMP we have one ICMP socket per-cpu.
 206  */
 207 static struct sock *icmp_sk(struct net *net)
 208 {
 209         return *this_cpu_ptr(net->ipv4.icmp_sk);
 210 }
 211
 212 static inline struct sock *icmp_xmit_lock(struct net *net)
 213 {
 214         struct sock *sk;
 215
 216         local_bh_disable();
 217
 218         sk = icmp_sk(net);
 219
 220         if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
 221                 /* This can happen if the output path signals a
 222                  * dst_link_failure() for an outgoing ICMP packet.
 223                  */
 224                 local_bh_enable();
 225                 return NULL;
 226         }
 227         return sk;
 228 }
 229
 230 static inline void icmp_xmit_unlock(struct sock *sk)
 231 {
 232         spin_unlock_bh(&sk->sk_lock.slock);
 233 }
 234
 235 int sysctl_icmp_msgs_per_sec __read_mostly = 1000;
 236 int sysctl_icmp_msgs_burst __read_mostly = 50;
 237
 238 static struct {
 239         spinlock_t      lock;
 240         u32             credit;
 241         u32             stamp;
 242 } icmp_global = {
 243         .lock           = __SPIN_LOCK_UNLOCKED(icmp_global.lock),
 244 };
 245
 246 /**
 247  * icmp_global_allow - Are we allowed to send one more ICMP message ?
 248  *
 249  * Uses a token bucket to limit our ICMP messages to ~sysctl_icmp_msgs_per_sec.
 250  * Returns false if we reached the limit and can not send another packet.
 251  * Note: called with BH disabled
 252  */
 253 bool icmp_global_allow(void)
 254 {
 255         u32 credit, delta, incr = 0, now = (u32)jiffies;
 256         bool rc = false;
 257
 258         /* Check if token bucket is empty and cannot be refilled
 259          * without taking the spinlock. The READ_ONCE() are paired
 260          * with the following WRITE_ONCE() in this same function.
 261          */
 262         if (!READ_ONCE(icmp_global.credit)) {
 263                 delta = min_t(u32, now - READ_ONCE(icmp_global.stamp), HZ);
 264                 if (delta < HZ / 50)
 265                         return false;
 266         }
 267
 268         spin_lock(&icmp_global.lock);
 269         delta = min_t(u32, now - icmp_global.stamp, HZ);
 270         if (delta >= HZ / 50) {
 271                 incr = sysctl_icmp_msgs_per_sec * delta / HZ ;
 272                 if (incr)
 273                         WRITE_ONCE(icmp_global.stamp, now);
 274         }
 275         credit = min_t(u32, icmp_global.credit + incr, sysctl_icmp_msgs_burst);
 276         if (credit) {
 277                 /* We want to use a credit of one in average, but need to randomize
 278                  * it for security reasons.
 279                  */
 280                 credit = max_t(int, credit - prandom_u32_max(3), 0);
 281                 rc = true;
 282         }
 283         WRITE_ONCE(icmp_global.credit, credit);
 284         spin_unlock(&icmp_global.lock);
 285         return rc;
 286 }
 287 EXPORT_SYMBOL(icmp_global_allow);
 288
 289 /*
 290  *      Send an ICMP frame.
 291  */
 292
 293 static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
 294                                struct flowi4 *fl4, int type, int code)
 295 {
 296         struct dst_entry *dst = &rt->dst;
 297         bool rc = true;
 298
 299         if (type > NR_ICMP_TYPES)
 300                 goto out;
 301
 302         /* Don't limit PMTU discovery. */
 303         if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
 304                 goto out;
 305
 306         /* No rate limit on loopback */
 307         if (dst->dev && (dst->dev->flags&IFF_LOOPBACK))
 308                 goto out;
 309
 310         /* Limit if icmp type is enabled in ratemask. */
 311         if (!((1 << type) & net->ipv4.sysctl_icmp_ratemask))
 312                 goto out;
 313
 314         rc = false;
 315         if (icmp_global_allow()) {
 316                 int vif = l3mdev_master_ifindex(dst->dev);
 317                 struct inet_peer *peer;
 318
 319                 peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, vif, 1);
 320                 rc = inet_peer_xrlim_allow(peer,
 321                                            net->ipv4.sysctl_icmp_ratelimit);
 322                 if (peer)
 323                         inet_putpeer(peer);
 324         }
 325 out:
 326         return rc;
 327 }
 328
 329 /*
 330  *      Maintain the counters used in the SNMP statistics for outgoing ICMP
 331  */
 332 void icmp_out_count(struct net *net, unsigned char type)
 333 {
 334         ICMPMSGOUT_INC_STATS(net, type);
 335         ICMP_INC_STATS(net, ICMP_MIB_OUTMSGS);
 336 }
 337
 338 /*
 339  *      Checksum each fragment, and on the first include the headers and final
 340  *      checksum.
 341  */
 342 static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd,
 343                           struct sk_buff *skb)
 344 {
 345         struct icmp_bxm *icmp_param = (struct icmp_bxm *)from;
 346         __wsum csum;
 347
 348         csum = skb_copy_and_csum_bits(icmp_param->skb,
 349                                       icmp_param->offset + offset,
 350                                       to, len, 0);
 351
 352         skb->csum = csum_block_add(skb->csum, csum, odd);
 353         if (icmp_pointers[icmp_param->data.icmph.type].error)
 354                 nf_ct_attach(skb, icmp_param->skb);
 355         return 0;
 356 }
 357
 358 static void icmp_push_reply(struct icmp_bxm *icmp_param,
 359                             struct flowi4 *fl4,
 360                             struct ipcm_cookie *ipc, struct rtable **rt)
 361 {
 362         struct sock *sk;
 363         struct sk_buff *skb;
 364
 365         sk = icmp_sk(dev_net((*rt)->dst.dev));
 366         if (ip_append_data(sk, fl4, icmp_glue_bits, icmp_param,
 367                            icmp_param->data_len+icmp_param->head_len,
 368                            icmp_param->head_len,
 369                            ipc, rt, MSG_DONTWAIT) < 0) {
 370                 __ICMP_INC_STATS(sock_net(sk), ICMP_MIB_OUTERRORS);
 371                 ip_flush_pending_frames(sk);
 372         } else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
 373                 struct icmphdr *icmph = icmp_hdr(skb);
 374                 __wsum csum = 0;
 375                 struct sk_buff *skb1;
 376
 377                 skb_queue_walk(&sk->sk_write_queue, skb1) {
 378                         csum = csum_add(csum, skb1->csum);
 379                 }
 380                 csum = csum_partial_copy_nocheck((void *)&icmp_param->data,
 381                                                  (char *)icmph,
 382                                                  icmp_param->head_len, csum);
 383                 icmph->checksum = csum_fold(csum);
 384                 skb->ip_summed = CHECKSUM_NONE;
 385                 ip_push_pending_frames(sk, fl4);
 386         }
 387 }
 388
 389 /*
 390  *      Driving logic for building and sending ICMP messages.
 391  */
 392
 393 static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 394 {
 395         struct ipcm_cookie ipc;
 396         struct rtable *rt = skb_rtable(skb);
 397         struct net *net = dev_net(rt->dst.dev);
 398         struct flowi4 fl4;
 399         struct sock *sk;
 400         struct inet_sock *inet;
 401         __be32 daddr, saddr;
 402         u32 mark = IP4_REPLY_MARK(net, skb->mark);
 403
 404         if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb))
 405                 return;
 406
 407         sk = icmp_xmit_lock(net);
 408         if (!sk)
 409                 return;
 410         inet = inet_sk(sk);
 411
 412         icmp_param->data.icmph.checksum = 0;
 413
 414         inet->tos = ip_hdr(skb)->tos;
 415         sk->sk_mark = mark;
 416         daddr = ipc.addr = ip_hdr(skb)->saddr;
 417         saddr = fib_compute_spec_dst(skb);
 418         ipc.opt = NULL;
 419         ipc.tx_flags = 0;
 420         ipc.ttl = 0;
 421         ipc.tos = -1;
 422
 423         if (icmp_param->replyopts.opt.opt.optlen) {
 424                 ipc.opt = &icmp_param->replyopts.opt;
 425                 if (ipc.opt->opt.srr)
 426                         daddr = icmp_param->replyopts.opt.opt.faddr;
 427         }
 428         memset(&fl4, 0, sizeof(fl4));
 429         fl4.daddr = daddr;
 430         fl4.saddr = saddr;
 431         fl4.flowi4_mark = mark;
 432         fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
 433         fl4.flowi4_proto = IPPROTO_ICMP;
 434         fl4.flowi4_oif = l3mdev_master_ifindex(skb->dev);
 435         security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
 436         rt = ip_route_output_key(net, &fl4);
 437         if (IS_ERR(rt))
 438                 goto out_unlock;
 439         if (icmpv4_xrlim_allow(net, rt, &fl4, icmp_param->data.icmph.type,
 440                                icmp_param->data.icmph.code))
 441                 icmp_push_reply(icmp_param, &fl4, &ipc, &rt);
 442         ip_rt_put(rt);
 443 out_unlock:
 444         icmp_xmit_unlock(sk);
 445 }
 446
 447 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 448
 449 /* Source and destination is swapped. See ip_multipath_icmp_hash */
 450 static int icmp_multipath_hash_skb(const struct sk_buff *skb)
 451 {
 452         const struct iphdr *iph = ip_hdr(skb);
 453
 454         return fib_multipath_hash(iph->daddr, iph->saddr);
 455 }
 456
 457 #else
 458
 459 #define icmp_multipath_hash_skb(skb) (-1)
 460
 461 #endif
 462
 463 /*
 464  * The device used for looking up which routing table to use for sending an ICMP
 465  * error is preferably the source whenever it is set, which should ensure the
 466  * icmp error can be sent to the source host, else lookup using the routing
 467  * table of the destination device, else use the main routing table (index 0).
 468  */
 469 static struct net_device *icmp_get_route_lookup_dev(struct sk_buff *skb)
 470 {
 471         struct net_device *route_lookup_dev = NULL;
 472
 473         if (skb->dev)
 474                 route_lookup_dev = skb->dev;
 475         else if (skb_dst(skb))
 476                 route_lookup_dev = skb_dst(skb)->dev;
 477         return route_lookup_dev;
 478 }
 479
 480 static struct rtable *icmp_route_lookup(struct net *net,
 481                                         struct flowi4 *fl4,
 482                                         struct sk_buff *skb_in,
 483                                         const struct iphdr *iph,
 484                                         __be32 saddr, u8 tos, u32 mark,
 485                                         int type, int code,
 486                                         struct icmp_bxm *param)
 487 {
 488         struct net_device *route_lookup_dev;
 489         struct rtable *rt, *rt2;
 490         struct flowi4 fl4_dec;
 491         int err;
 492
 493         memset(fl4, 0, sizeof(*fl4));
 494         fl4->daddr = (param->replyopts.opt.opt.srr ?
 495                       param->replyopts.opt.opt.faddr : iph->saddr);
 496         fl4->saddr = saddr;
 497         fl4->flowi4_mark = mark;
 498         fl4->flowi4_tos = RT_TOS(tos);
 499         fl4->flowi4_proto = IPPROTO_ICMP;
 500         fl4->fl4_icmp_type = type;
 501         fl4->fl4_icmp_code = code;
 502         route_lookup_dev = icmp_get_route_lookup_dev(skb_in);
 503         fl4->flowi4_oif = l3mdev_master_ifindex(route_lookup_dev);
 504
 505         security_skb_classify_flow(skb_in, flowi4_to_flowi(fl4));
 506         rt = __ip_route_output_key_hash(net, fl4,
 507                                         icmp_multipath_hash_skb(skb_in));
 508         if (IS_ERR(rt))
 509                 return rt;
 510
 511         /* No need to clone since we're just using its address. */
 512         rt2 = rt;
 513
 514         rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
 515                                            flowi4_to_flowi(fl4), NULL, 0);
 516         if (!IS_ERR(rt)) {
 517                 if (rt != rt2)
 518                         return rt;
 519         } else if (PTR_ERR(rt) == -EPERM) {
 520                 rt = NULL;
 521         } else
 522                 return rt;
 523
 524         err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4_dec), AF_INET);
 525         if (err)
 526                 goto relookup_failed;
 527
 528         if (inet_addr_type_dev_table(net, route_lookup_dev,
 529                                      fl4_dec.saddr) == RTN_LOCAL) {
 530                 rt2 = __ip_route_output_key(net, &fl4_dec);
 531                 if (IS_ERR(rt2))
 532                         err = PTR_ERR(rt2);
 533         } else {
 534                 struct flowi4 fl4_2 = {};
 535                 unsigned long orefdst;
 536
 537                 fl4_2.daddr = fl4_dec.saddr;
 538                 rt2 = ip_route_output_key(net, &fl4_2);
 539                 if (IS_ERR(rt2)) {
 540                         err = PTR_ERR(rt2);
 541                         goto relookup_failed;
 542                 }
 543                 /* Ugh! */
 544                 orefdst = skb_in->_skb_refdst; /* save old refdst */
 545                 skb_dst_set(skb_in, NULL);
 546                 err = ip_route_input(skb_in, fl4_dec.daddr, fl4_dec.saddr,
 547                                      RT_TOS(tos), rt2->dst.dev);
 548
 549                 dst_release(&rt2->dst);
 550                 rt2 = skb_rtable(skb_in);
 551                 skb_in->_skb_refdst = orefdst; /* restore old refdst */
 552         }
 553
 554         if (err)
 555                 goto relookup_failed;
 556
 557         rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst,
 558                                             flowi4_to_flowi(&fl4_dec), NULL,
 559                                             XFRM_LOOKUP_ICMP);
 560         if (!IS_ERR(rt2)) {
 561                 dst_release(&rt->dst);
 562                 memcpy(fl4, &fl4_dec, sizeof(*fl4));
 563                 rt = rt2;
 564         } else if (PTR_ERR(rt2) == -EPERM) {
 565                 if (rt)
 566                         dst_release(&rt->dst);
 567                 return rt2;
 568         } else {
 569                 err = PTR_ERR(rt2);
 570                 goto relookup_failed;
 571         }
 572         return rt;
 573
 574 relookup_failed:
 575         if (rt)
 576                 return rt;
 577         return ERR_PTR(err);
 578 }
 579
 580 /*
 581  *      Send an ICMP message in response to a situation
 582  *
 583  *      RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header.
 584  *                MAY send more (we do).
 585  *                      MUST NOT change this header information.
 586  *                      MUST NOT reply to a multicast/broadcast IP address.
 587  *                      MUST NOT reply to a multicast/broadcast MAC address.
 588  *                      MUST reply to only the first fragment.
 589  */
 590
 591 void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info,
 592                  const struct ip_options *opt)
 593 {
 594         struct iphdr *iph;
 595         int room;
 596         struct icmp_bxm *icmp_param;
 597         struct rtable *rt = skb_rtable(skb_in);
 598         struct ipcm_cookie ipc;
 599         struct flowi4 fl4;
 600         __be32 saddr;
 601         u8  tos;
 602         u32 mark;
 603         struct net *net;
 604         struct sock *sk;
 605
 606         if (!rt)
 607                 goto out;
 608         net = dev_net(rt->dst.dev);
 609
 610         /*
 611          *      Find the original header. It is expected to be valid, of course.
 612          *      Check this, icmp_send is called from the most obscure devices
 613          *      sometimes.
 614          */
 615         iph = ip_hdr(skb_in);
 616
 617         if ((u8 *)iph < skb_in->head ||
 618             (skb_network_header(skb_in) + sizeof(*iph)) >
 619             skb_tail_pointer(skb_in))
 620                 goto out;
 621
 622         /*
 623          *      No replies to physical multicast/broadcast
 624          */
 625         if (skb_in->pkt_type != PACKET_HOST)
 626                 goto out;
 627
 628         /*
 629          *      Now check at the protocol level
 630          */
 631         if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
 632                 goto out;
 633
 634         /*
 635          *      Only reply to fragment 0. We byte re-order the constant
 636          *      mask for efficiency.
 637          */
 638         if (iph->frag_off & htons(IP_OFFSET))
 639                 goto out;
 640
 641         /*
 642          *      If we send an ICMP error to an ICMP error a mess would result..
 643          */
 644         if (icmp_pointers[type].error) {
 645                 /*
 646                  *      We are an error, check if we are replying to an
 647                  *      ICMP error
 648                  */
 649                 if (iph->protocol == IPPROTO_ICMP) {
 650                         u8 _inner_type, *itp;
 651
 652                         itp = skb_header_pointer(skb_in,
 653                                                  skb_network_header(skb_in) +
 654                                                  (iph->ihl << 2) +
 655                                                  offsetof(struct icmphdr,
 656                                                           type) -
 657                                                  skb_in->data,
 658                                                  sizeof(_inner_type),
 659                                                  &_inner_type);
 660                         if (!itp)
 661                                 goto out;
 662
 663                         /*
 664                          *      Assume any unknown ICMP type is an error. This
 665                          *      isn't specified by the RFC, but think about it..
 666                          */
 667                         if (*itp > NR_ICMP_TYPES ||
 668                             icmp_pointers[*itp].error)
 669                                 goto out;
 670                 }
 671         }
 672
 673         icmp_param = kmalloc(sizeof(*icmp_param), GFP_ATOMIC);
 674         if (!icmp_param)
 675                 return;
 676
 677         sk = icmp_xmit_lock(net);
 678         if (!sk)
 679                 goto out_free;
 680
 681         /*
 682          *      Construct source address and options.
 683          */
 684
 685         saddr = iph->daddr;
 686         if (!(rt->rt_flags & RTCF_LOCAL)) {
 687                 struct net_device *dev = NULL;
 688
 689                 rcu_read_lock();
 690                 if (rt_is_input_route(rt) &&
 691                     net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr)
 692                         dev = dev_get_by_index_rcu(net, inet_iif(skb_in));
 693
 694                 if (dev)
 695                         saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK);
 696                 else
 697                         saddr = 0;
 698                 rcu_read_unlock();
 699         }
 700
 701         tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) |
 702                                            IPTOS_PREC_INTERNETCONTROL) :
 703                                           iph->tos;
 704         mark = IP4_REPLY_MARK(net, skb_in->mark);
 705
 706         if (__ip_options_echo(&icmp_param->replyopts.opt.opt, skb_in, opt))
 707                 goto out_unlock;
 708
 709
 710         /*
 711          *      Prepare data for ICMP header.
 712          */
 713
 714         icmp_param->data.icmph.type      = type;
 715         icmp_param->data.icmph.code      = code;
 716         icmp_param->data.icmph.un.gateway = info;
 717         icmp_param->data.icmph.checksum  = 0;
 718         icmp_param->skb   = skb_in;
 719         icmp_param->offset = skb_network_offset(skb_in);
 720         inet_sk(sk)->tos = tos;
 721         sk->sk_mark = mark;
 722         ipc.addr = iph->saddr;
 723         ipc.opt = &icmp_param->replyopts.opt;
 724         ipc.tx_flags = 0;
 725         ipc.ttl = 0;
 726         ipc.tos = -1;
 727
 728         rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos, mark,
 729                                type, code, icmp_param);
 730         if (IS_ERR(rt))
 731                 goto out_unlock;
 732
 733         if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code))
 734                 goto ende;
 735
 736         /* RFC says return as much as we can without exceeding 576 bytes. */
 737
 738         room = dst_mtu(&rt->dst);
 739         if (room > 576)
 740                 room = 576;
 741         room -= sizeof(struct iphdr) + icmp_param->replyopts.opt.opt.optlen;
 742         room -= sizeof(struct icmphdr);
 743
 744         icmp_param->data_len = skb_in->len - icmp_param->offset;
 745         if (icmp_param->data_len > room)
 746                 icmp_param->data_len = room;
 747         icmp_param->head_len = sizeof(struct icmphdr);
 748
 749         icmp_push_reply(icmp_param, &fl4, &ipc, &rt);
 750 ende:
 751         ip_rt_put(rt);
 752 out_unlock:
 753         icmp_xmit_unlock(sk);
 754 out_free:
 755         kfree(icmp_param);
 756 out:;
 757 }
 758 EXPORT_SYMBOL(__icmp_send);
 759
 760 #if IS_ENABLED(CONFIG_NF_NAT)
 761 #include <net/netfilter/nf_conntrack.h>
 762 void icmp_ndo_send(struct sk_buff *skb_in, int type, int code, __be32 info)
 763 {
 764         struct sk_buff *cloned_skb = NULL;
 765         struct ip_options opts = { 0 };
 766         enum ip_conntrack_info ctinfo;
 767         struct nf_conn *ct;
 768         __be32 orig_ip;
 769
 770         ct = nf_ct_get(skb_in, &ctinfo);
 771         if (!ct || !(ct->status & IPS_SRC_NAT)) {
 772                 __icmp_send(skb_in, type, code, info, &opts);
 773                 return;
 774         }
 775
 776         if (skb_shared(skb_in))
 777                 skb_in = cloned_skb = skb_clone(skb_in, GFP_ATOMIC);
 778
 779         if (unlikely(!skb_in || skb_network_header(skb_in) < skb_in->head ||
 780             (skb_network_header(skb_in) + sizeof(struct iphdr)) >
 781             skb_tail_pointer(skb_in) || skb_ensure_writable(skb_in,
 782             skb_network_offset(skb_in) + sizeof(struct iphdr))))
 783                 goto out;
 784
 785         orig_ip = ip_hdr(skb_in)->saddr;
 786         ip_hdr(skb_in)->saddr = ct->tuplehash[0].tuple.src.u3.ip;
 787         __icmp_send(skb_in, type, code, info, &opts);
 788         ip_hdr(skb_in)->saddr = orig_ip;
 789 out:
 790         consume_skb(cloned_skb);
 791 }
 792 EXPORT_SYMBOL(icmp_ndo_send);
 793 #endif
 794
 795 static void icmp_socket_deliver(struct sk_buff *skb, u32 info)
 796 {
 797         const struct iphdr *iph = (const struct iphdr *) skb->data;
 798         const struct net_protocol *ipprot;
 799         int protocol = iph->protocol;
 800
 801         /* Checkin full IP header plus 8 bytes of protocol to
 802          * avoid additional coding at protocol handlers.
 803          */
 804         if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) {
 805                 __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS);
 806                 return;
 807         }
 808
 809         raw_icmp_error(skb, protocol, info);
 810
 811         ipprot = rcu_dereference(inet_protos[protocol]);
 812         if (ipprot && ipprot->err_handler)
 813                 ipprot->err_handler(skb, info);
 814 }
 815
 816 static bool icmp_tag_validation(int proto)
 817 {
 818         bool ok;
 819
 820         rcu_read_lock();
 821         ok = rcu_dereference(inet_protos[proto])->icmp_strict_tag_validation;
 822         rcu_read_unlock();
 823         return ok;
 824 }
 825
 826 /*
 827  *      Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEEDED, ICMP_QUENCH, and
 828  *      ICMP_PARAMETERPROB.
 829  */
 830
 831 static bool icmp_unreach(struct sk_buff *skb)
 832 {
 833         const struct iphdr *iph;
 834         struct icmphdr *icmph;
 835         struct net *net;
 836         u32 info = 0;
 837
 838         net = dev_net(skb_dst(skb)->dev);
 839
 840         /*
 841          *      Incomplete header ?
 842          *      Only checks for the IP header, there should be an
 843          *      additional check for longer headers in upper levels.
 844          */
 845
 846         if (!pskb_may_pull(skb, sizeof(struct iphdr)))
 847                 goto out_err;
 848
 849         icmph = icmp_hdr(skb);
 850         iph   = (const struct iphdr *)skb->data;
 851
 852         if (iph->ihl < 5) /* Mangled header, drop. */
 853                 goto out_err;
 854
 855         switch (icmph->type) {
 856         case ICMP_DEST_UNREACH:
 857                 switch (icmph->code & 15) {
 858                 case ICMP_NET_UNREACH:
 859                 case ICMP_HOST_UNREACH:
 860                 case ICMP_PROT_UNREACH:
 861                 case ICMP_PORT_UNREACH:
 862                         break;
 863                 case ICMP_FRAG_NEEDED:
 864                         /* for documentation of the ip_no_pmtu_disc
 865                          * values please see
 866                          * Documentation/networking/ip-sysctl.txt
 867                          */
 868                         switch (net->ipv4.sysctl_ip_no_pmtu_disc) {
 869                         default:
 870                                 net_dbg_ratelimited("%pI4: fragmentation needed and DF set\n",
 871                                                     &iph->daddr);
 872                                 break;
 873                         case 2:
 874                                 goto out;
 875                         case 3:
 876                                 if (!icmp_tag_validation(iph->protocol))
 877                                         goto out;
 878                                 /* fall through */
 879                         case 0:
 880                                 info = ntohs(icmph->un.frag.mtu);
 881                         }
 882                         break;
 883                 case ICMP_SR_FAILED:
 884                         net_dbg_ratelimited("%pI4: Source Route Failed\n",
 885                                             &iph->daddr);
 886                         break;
 887                 default:
 888                         break;
 889                 }
 890                 if (icmph->code > NR_ICMP_UNREACH)
 891                         goto out;
 892                 break;
 893         case ICMP_PARAMETERPROB:
 894                 info = ntohl(icmph->un.gateway) >> 24;
 895                 break;
 896         case ICMP_TIME_EXCEEDED:
 897                 __ICMP_INC_STATS(net, ICMP_MIB_INTIMEEXCDS);
 898                 if (icmph->code == ICMP_EXC_FRAGTIME)
 899                         goto out;
 900                 break;
 901         }
 902
 903         /*
 904          *      Throw it at our lower layers
 905          *
 906          *      RFC 1122: 3.2.2 MUST extract the protocol ID from the passed
 907          *                header.
 908          *      RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the
 909          *                transport layer.
 910          *      RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to
 911          *                transport layer.
 912          */
 913
 914         /*
 915          *      Check the other end isn't violating RFC 1122. Some routers send
 916          *      bogus responses to broadcast frames. If you see this message
 917          *      first check your netmask matches at both ends, if it does then
 918          *      get the other vendor to fix their kit.
 919          */
 920
 921         if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses &&
 922             inet_addr_type_dev_table(net, skb->dev, iph->daddr) == RTN_BROADCAST) {
 923                 net_warn_ratelimited("%pI4 sent an invalid ICMP type %u, code %u error to a broadcast: %pI4 on %s\n",
 924                                      &ip_hdr(skb)->saddr,
 925                                      icmph->type, icmph->code,
 926                                      &iph->daddr, skb->dev->name);
 927                 goto out;
 928         }
 929
 930         icmp_socket_deliver(skb, info);
 931
 932 out:
 933         return true;
 934 out_err:
 935         __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
 936         return false;
 937 }
 938
 939
 940 /*
 941  *      Handle ICMP_REDIRECT.
 942  */
 943
 944 static bool icmp_redirect(struct sk_buff *skb)
 945 {
 946         if (skb->len < sizeof(struct iphdr)) {
 947                 __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS);
 948                 return false;
 949         }
 950
 951         if (!pskb_may_pull(skb, sizeof(struct iphdr))) {
 952                 /* there aught to be a stat */
 953                 return false;
 954         }
 955
 956         icmp_socket_deliver(skb, icmp_hdr(skb)->un.gateway);
 957         return true;
 958 }
 959
 960 /*
 961  *      Handle ICMP_ECHO ("ping") requests.
 962  *
 963  *      RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo
 964  *                requests.
 965  *      RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be
 966  *                included in the reply.
 967  *      RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring
 968  *                echo requests, MUST have default=NOT.
 969  *      See also WRT handling of options once they are done and working.
 970  */
 971
 972 static bool icmp_echo(struct sk_buff *skb)
 973 {
 974         struct net *net;
 975
 976         net = dev_net(skb_dst(skb)->dev);
 977         if (!net->ipv4.sysctl_icmp_echo_ignore_all) {
 978                 struct icmp_bxm icmp_param;
 979
 980                 icmp_param.data.icmph      = *icmp_hdr(skb);
 981                 icmp_param.data.icmph.type = ICMP_ECHOREPLY;
 982                 icmp_param.skb             = skb;
 983                 icmp_param.offset          = 0;
 984                 icmp_param.data_len        = skb->len;
 985                 icmp_param.head_len        = sizeof(struct icmphdr);
 986                 icmp_reply(&icmp_param, skb);
 987         }
 988         /* should there be an ICMP stat for ignored echos? */
 989         return true;
 990 }
 991
 992 /*
 993  *      Handle ICMP Timestamp requests.
 994  *      RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests.
 995  *                SHOULD be in the kernel for minimum random latency.
 996  *                MUST be accurate to a few minutes.
 997  *                MUST be updated at least at 15Hz.
 998  */
 999 static bool icmp_timestamp(struct sk_buff *skb)
1000 {
1001         struct icmp_bxm icmp_param;
1002         /*
1003          *      Too short.
1004          */
1005         if (skb->len < 4)
1006                 goto out_err;
1007
1008         /*
1009          *      Fill in the current time as ms since midnight UT:
1010          */
1011         icmp_param.data.times[1] = inet_current_timestamp();
1012         icmp_param.data.times[2] = icmp_param.data.times[1];
1013         if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4))
1014                 BUG();
1015         icmp_param.data.icmph      = *icmp_hdr(skb);
1016         icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY;
1017         icmp_param.data.icmph.code = 0;
1018         icmp_param.skb             = skb;
1019         icmp_param.offset          = 0;
1020         icmp_param.data_len        = 0;
1021         icmp_param.head_len        = sizeof(struct icmphdr) + 12;
1022         icmp_reply(&icmp_param, skb);
1023         return true;
1024
1025 out_err:
1026         __ICMP_INC_STATS(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS);
1027         return false;
1028 }
1029
1030 static bool icmp_discard(struct sk_buff *skb)
1031 {
1032         /* pretend it was a success */
1033         return true;
1034 }
1035
1036 /*
1037  *      Deal with incoming ICMP packets.
1038  */
1039 int icmp_rcv(struct sk_buff *skb)
1040 {
1041         struct icmphdr *icmph;
1042         struct rtable *rt = skb_rtable(skb);
1043         struct net *net = dev_net(rt->dst.dev);
1044         bool success;
1045
1046         if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1047                 struct sec_path *sp = skb_sec_path(skb);
1048                 int nh;
1049
1050                 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
1051                                  XFRM_STATE_ICMP))
1052                         goto drop;
1053
1054                 if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr)))
1055                         goto drop;
1056
1057                 nh = skb_network_offset(skb);
1058                 skb_set_network_header(skb, sizeof(*icmph));
1059
1060                 if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
1061                         goto drop;
1062
1063                 skb_set_network_header(skb, nh);
1064         }
1065
1066         __ICMP_INC_STATS(net, ICMP_MIB_INMSGS);
1067
1068         if (skb_checksum_simple_validate(skb))
1069                 goto csum_error;
1070
1071         if (!pskb_pull(skb, sizeof(*icmph)))
1072                 goto error;
1073
1074         icmph = icmp_hdr(skb);
1075
1076         ICMPMSGIN_INC_STATS(net, icmph->type);
1077         /*
1078          *      18 is the highest 'known' ICMP type. Anything else is a mystery
1079          *
1080          *      RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently
1081          *                discarded.
1082          */
1083         if (icmph->type > NR_ICMP_TYPES)
1084                 goto error;
1085
1086
1087         /*
1088          *      Parse the ICMP message
1089          */
1090
1091         if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1092                 /*
1093                  *      RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be
1094                  *        silently ignored (we let user decide with a sysctl).
1095                  *      RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently
1096                  *        discarded if to broadcast/multicast.
1097                  */
1098                 if ((icmph->type == ICMP_ECHO ||
1099                      icmph->type == ICMP_TIMESTAMP) &&
1100                     net->ipv4.sysctl_icmp_echo_ignore_broadcasts) {
1101                         goto error;
1102                 }
1103                 if (icmph->type != ICMP_ECHO &&
1104                     icmph->type != ICMP_TIMESTAMP &&
1105                     icmph->type != ICMP_ADDRESS &&
1106                     icmph->type != ICMP_ADDRESSREPLY) {
1107                         goto error;
1108                 }
1109         }
1110
1111         success = icmp_pointers[icmph->type].handler(skb);
1112
1113         if (success)  {
1114                 consume_skb(skb);
1115                 return 0;
1116         }
1117
1118 drop:
1119         kfree_skb(skb);
1120         return 0;
1121 csum_error:
1122         __ICMP_INC_STATS(net, ICMP_MIB_CSUMERRORS);
1123 error:
1124         __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
1125         goto drop;
1126 }
1127
1128 void icmp_err(struct sk_buff *skb, u32 info)
1129 {
1130         struct iphdr *iph = (struct iphdr *)skb->data;
1131         int offset = iph->ihl<<2;
1132         struct icmphdr *icmph = (struct icmphdr *)(skb->data + offset);
1133         int type = icmp_hdr(skb)->type;
1134         int code = icmp_hdr(skb)->code;
1135         struct net *net = dev_net(skb->dev);
1136
1137         /*
1138          * Use ping_err to handle all icmp errors except those
1139          * triggered by ICMP_ECHOREPLY which sent from kernel.
1140          */
1141         if (icmph->type != ICMP_ECHOREPLY) {
1142                 ping_err(skb, offset, info);
1143                 return;
1144         }
1145
1146         if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
1147                 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ICMP, 0);
1148         else if (type == ICMP_REDIRECT)
1149                 ipv4_redirect(skb, net, 0, 0, IPPROTO_ICMP, 0);
1150 }
1151
1152 /*
1153  *      This table is the definition of how we handle ICMP.
1154  */
1155 static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = {
1156         [ICMP_ECHOREPLY] = {
1157                 .handler = ping_rcv,
1158         },
1159         [1] = {
1160                 .handler = icmp_discard,
1161                 .error = 1,
1162         },
1163         [2] = {
1164                 .handler = icmp_discard,
1165                 .error = 1,
1166         },
1167         [ICMP_DEST_UNREACH] = {
1168                 .handler = icmp_unreach,
1169                 .error = 1,
1170         },
1171         [ICMP_SOURCE_QUENCH] = {
1172                 .handler = icmp_unreach,
1173                 .error = 1,
1174         },
1175         [ICMP_REDIRECT] = {
1176                 .handler = icmp_redirect,
1177                 .error = 1,
1178         },
1179         [6] = {
1180                 .handler = icmp_discard,
1181                 .error = 1,
1182         },
1183         [7] = {
1184                 .handler = icmp_discard,
1185                 .error = 1,
1186         },
1187         [ICMP_ECHO] = {
1188                 .handler = icmp_echo,
1189         },
1190         [9] = {
1191                 .handler = icmp_discard,
1192                 .error = 1,
1193         },
1194         [10] = {
1195                 .handler = icmp_discard,
1196                 .error = 1,
1197         },
1198         [ICMP_TIME_EXCEEDED] = {
1199                 .handler = icmp_unreach,
1200                 .error = 1,
1201         },
1202         [ICMP_PARAMETERPROB] = {
1203                 .handler = icmp_unreach,
1204                 .error = 1,
1205         },
1206         [ICMP_TIMESTAMP] = {
1207                 .handler = icmp_timestamp,
1208         },
1209         [ICMP_TIMESTAMPREPLY] = {
1210                 .handler = icmp_discard,
1211         },
1212         [ICMP_INFO_REQUEST] = {
1213                 .handler = icmp_discard,
1214         },
1215         [ICMP_INFO_REPLY] = {
1216                 .handler = icmp_discard,
1217         },
1218         [ICMP_ADDRESS] = {
1219                 .handler = icmp_discard,
1220         },
1221         [ICMP_ADDRESSREPLY] = {
1222                 .handler = icmp_discard,
1223         },
1224 };
1225
1226 static void __net_exit icmp_sk_exit(struct net *net)
1227 {
1228         int i;
1229
1230         for_each_possible_cpu(i)
1231                 inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.icmp_sk, i));
1232         free_percpu(net->ipv4.icmp_sk);
1233         net->ipv4.icmp_sk = NULL;
1234 }
1235
1236 static int __net_init icmp_sk_init(struct net *net)
1237 {
1238         int i, err;
1239
1240         net->ipv4.icmp_sk = alloc_percpu(struct sock *);
1241         if (!net->ipv4.icmp_sk)
1242                 return -ENOMEM;
1243
1244         for_each_possible_cpu(i) {
1245                 struct sock *sk;
1246
1247                 err = inet_ctl_sock_create(&sk, PF_INET,
1248                                            SOCK_RAW, IPPROTO_ICMP, net);
1249                 if (err < 0)
1250                         goto fail;
1251
1252                 *per_cpu_ptr(net->ipv4.icmp_sk, i) = sk;
1253
1254                 /* Enough space for 2 64K ICMP packets, including
1255                  * sk_buff/skb_shared_info struct overhead.
1256                  */
1257                 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
1258
1259                 /*
1260                  * Speedup sock_wfree()
1261                  */
1262                 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1263                 inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT;
1264         }
1265
1266         /* Control parameters for ECHO replies. */
1267         net->ipv4.sysctl_icmp_echo_ignore_all = 0;
1268         net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1;
1269
1270         /* Control parameter - ignore bogus broadcast responses? */
1271         net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1;
1272
1273         /*
1274          *      Configurable global rate limit.
1275          *
1276          *      ratelimit defines tokens/packet consumed for dst->rate_token
1277          *      bucket ratemask defines which icmp types are ratelimited by
1278          *      setting it's bit position.
1279          *
1280          *      default:
1281          *      dest unreachable (3), source quench (4),
1282          *      time exceeded (11), parameter problem (12)
1283          */
1284
1285         net->ipv4.sysctl_icmp_ratelimit = 1 * HZ;
1286         net->ipv4.sysctl_icmp_ratemask = 0x1818;
1287         net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0;
1288
1289         return 0;
1290
1291 fail:
1292         for_each_possible_cpu(i)
1293                 inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.icmp_sk, i));
1294         free_percpu(net->ipv4.icmp_sk);
1295         return err;
1296 }
1297
1298 static struct pernet_operations __net_initdata icmp_sk_ops = {
1299        .init = icmp_sk_init,
1300        .exit = icmp_sk_exit,
1301 };
1302
1303 int __init icmp_init(void)
1304 {
1305         return register_pernet_subsys(&icmp_sk_ops);
1306 }